Mound City is a city and the county seat of Pulaski County, Illinois, United States. It is located along the Ohio River just north of its confluence with the Mississippi River. As of the 2010 census, the city population was 588.

Pulaski County is a county located in the U.S. state of Illinois. According to the 2020 census, it had a population of 5,193. Its county seat is Mound City. Its largest city is Mounds. It is located along the Ohio River in the southwestern portion of the state, known locally as "Little Egypt".